Jan. 20, 1937
397
ISOMERIZATION OF cis-a,a'-DIMETHYLSTILBENE TO trans ISOMER
Reconversion of Acid I1 to Nitrile Ia.-2,3-Diphenylbutyryl chloride (9 g., 0.035 mole), prepared as described above, was stirred with 100 mi. of concentrated aqueous ammonia for one hour. The suspended solid was removed by filtration, dried and crystallized from benzene to give 5 g. (60%) of 2,3-diphenylbutyramide, m.p. 193-193.5", reported4 m.p. 193'. T h e amide (4 g., 0.017 mole) was heated with 20 ml. of thionyl chloride, and the solution poured on crushed ice. The resulting solid was crystallized from acetone and water t o give 2.6 g. (70%) of 2,3-diphenylbutyronitrile (Ia), m.p. 132-133". The melting point was not depressed on admixture with a sample of the nitrile obtained by the aphenylethylation of potassiophenylacetonitrile in liquid ammonia. *
[CONTRIBUTION FROM
THE
Isomerization of threo-Nitrile (Ib) to eryfhro-Nitrile (Ia) .threo-2,3-Diphenylbutyronitrile (Ib) (5.9 g., 0.025 mole), prepared by the a-phenylethylation of potassiophenylacetonitrile in ether,2 was dissolved in 50 ml. of anhydrous ether, and the solution added within one minute t o a stirred solution of 0.0025 mole of potassiophenylacetonitrile in 100 ml. of liquid ammonia (prepared from potassiumamide andphenylacetonitrile).2 After stirring 10 minutes, 1 g. of solid ammonium chloride was added, and the reaction mixture worked up to give 5.7 g. (9770) of erythro-2,3-diphenylbutyronitrile (Ia), m.p. 131-133'. One recrystallization from acetone and water gave 5.4 g. (92Y0b) of this product melting a t 132-133", showing no depression when mixed with an authentic sample. DURHAM, Tu'. C.
DEPARTMENT O F CHEMISTRY, DUKEUNIVERSITY]
Self-alkylation of a-Phenylethyl Chloride to Form Isomeric Dimeric Halides and Dimeric Olefins by Amide Ion. Isomerization of cis-&,&'-Dimethylstilbene to trans Isomer1 BY WALLACE I
